Display device for vehicles

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device for vehicles, and more particularly, to a display device equipped with a light control device capable of adjusting the luminance of a light source according to the brightness of the surroundings.

2. Description of the Background Art

In an automobile or a motorcycle, a display device which displays vehicle speed, engine speed, etc. is provided with an illuminating system for illuminating a display surface, that is, an instrument panel surface. Some illuminating systems are fitted with a light control device which can detect the external light by a sensor and adjust the luminance of the light source in accordance with the detected output. However, it is likely that sensor characteristics will be deteriorated by heat, ultraviolet rays or infrared rays of the external light, resulting in inaccurate light control. To cope with this shortcoming, therefore, there has been proposed by Japanese Utility Model Publication No. 2582395 a head-up type display device which guides the external light to the sensor by a light guide body having a characteristic to cut the ultraviolet rays and infrared rays.

Generally, the sensor and the light guide member for the light control device are located in a place, for example on an instrument panel directly exposed to the external light, or, in a motorcycle, in the vicinity of a windshield supporting portion. Therefore, the display screen of the display device is sometimes shaded by the instrument panel or the light is reduced by a visor mounted above the display device even when the surroundings are bright. In such a case, if the luminance is adjusted according to the detected output of the sensor, the display screen is not necessarily bright to the rider (or driver).

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a display device for vehicles which is capable of accurately detecting the easy-to-view luminance on the display screen, and controlling the light according to a result of the detection.

To attain the above-described object, the display device of this invention has a light control means for controlling the illumination on the display surface according to the illumination detected by the light sensor.

The display device includes a case, an instrument panel housed in the case, and a lighting means for illuminating the instrument panel. The light sensor is located on the surface of the instrument panel. The light sensor for light control is disposed on the surface of the instrument panel for practical visual recognition by the rider (or driver). Because of the provision of the light sensor, the rider (or driver) can see results of measurements of the vehicle speed and others at an easier-to-recognize illumination.

The lighting means is disposed on the back side of the instrument panel, and a light shielding means is provided for shielding the light of the lighting means coming from behind the light sensor. The light from the lighting means can therefore be prevented from directly entering the light sensor.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 is a front view of a meter unit according to one embodiment of this invention;

FIG. 2 is a side sectional view of the meter unit;

FIG. 3 is a perspective view of a panel cover;

FIG. 4 is a block diagram showing a major portion of the light control device; and

FIG. 5 is a side view of a motorcycle mounted with a display device according to one embodiment of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of a display device for vehicles according to this invention will now be described with reference to the accompanying drawings. FIG. 5 is a side view showing the external appearance of a motorcycle mounted with a display device according to the one preferred embodiment of this invention. In the drawing, the motorcycle <b>1</b> (hereinafter referred to as the vehicle) is mounted with a horizontal opposed six-cylinder engine <b>2</b>.

The frame structure of the vehicle is comprised of a twin-frame type main frame <b>4</b> which is bifurcated to right and left frames extending rearwardly from a steering head <b>3</b>, and a rear frame <b>5</b> connected to the rear end of the main frame <b>4</b>. A front fork <b>6</b> is composed of two pipes arranged on the right and left sides in the direction of travel, and is installed to the steering head <b>3</b>. The front fork <b>6</b> is thus rotatable in the steering direction.

A handlebar <b>7</b> is secured on the upper part of the steering head <b>3</b>, on the top bridge. A front wheel axle <b>8</b> is mounted at the lower end of the front fork <b>6</b>. A front wheel <b>9</b> is rotatably supported on the front wheel axle <b>8</b>.

The display device is mounted forwardly of the handlebar <b>7</b>. The display device includes a meter unit <b>10</b>, including a display panel and a control unit. A visor <b>50</b> is provided for the meter unit <b>10</b> for protecting the meter unit <b>10</b> from the external light. The visor <b>50</b> is for shading the upper part of the display surface of the meter unit <b>10</b>. To shade the lower display surface, a non-illustrated second visor is further provided. A display surface illuminating system is installed on the meter unit <b>10</b>, and a light control device is installed for adjusting the luminance of the illuminating system. The visor and light control device will be described in detail later.

A lens surface (clear lens) <b>12</b> for the lighting device is attached at the front of a front fairing (cowling) <b>11</b> which covers the front part of the vehicle <b>1</b>. A ballast <b>13</b> is housed inside of the front cowling <b>11</b> for a discharge lamp used as the lighting device. A windshield <b>14</b> is installed above the front cowling <b>11</b>, and an air inlet <b>15</b> is formed near the mounting portion of the windshield <b>14</b>.

A fuel tank <b>16</b> is mounted on the main frame <b>4</b>. A rider's seat <b>17</b> and a pillion seat <b>18</b> are arranged to the rear of the fuel tank <b>16</b>. The rider's seat <b>17</b> and the pillion seat <b>18</b> are mounted on the rear frame <b>5</b>. The pillion seat <b>18</b> is formed unitarily with the rider's seat <b>17</b>, and has a backrest <b>19</b>. A rear trunk <b>20</b> is provided behind the backrest <b>19</b>. A rear stop light <b>21</b> and a blinker light <b>22</b> are also mounted behind the rear trunk <b>20</b>. Side trunks <b>23</b> are mounted beneath the rear trunk <b>20</b> on the right and left of the rear wheel <b>26</b>. A set of rear stop lights <b>24</b> and blinker lights <b>25</b> are mounted at the rear of the side trunks <b>23</b>.

An air cleaner <b>27</b> is mounted forwardly of the lower part of the fuel tank <b>16</b>. An intake manifold <b>29</b> extends from a throttle body <b>28</b> mounted in front of the air cleaner <b>27</b>. The intake manifold <b>29</b> is connected to each of three cylinders oppositely arranged on both the right and left sides of the vehicle. A fuel injection system (not shown) is located upstream of each of these cylinders. An exhaust manifold <b>30</b> is installed from the engine <b>2</b> toward the rear. The exhaust manifold <b>30</b> is connected to a muffler <b>31</b>.

Both sides under the rider's seat <b>17</b> are covered with side covers <b>32</b>, and a front lower cowling <b>33</b> is located at the front of the engine <b>2</b>. A rear cushion <b>34</b> is disposed under the rider's seat <b>17</b>. The rear cushion <b>34</b> is connected to a hydraulic unit (not shown) which is capable of electrically adjusting the spring force to provide the initial weight application to the suspension according to the rider's weight. The vehicle <b>1</b> can be supported up on a stand <b>35</b>.

Next, the panel face of the meter unit <b>10</b> will be explained. FIG. 1 is a plan view of the meter unit as viewed from the rider's seat side of the motorcycle. In FIG. 1, the speedometer <b>110</b> is located at the central part of the instrument panel <b>100</b> mounted above the meter unit <b>10</b>. Mounted on the left is a tachometer <b>120</b>, and mounted on the right are a fuel gauge <b>130</b> and a water temperature gauge <b>140</b>. An information display panel <b>150</b> is provided beneath the instrument panel <b>100</b> which displays information, characters, and other graphic symbols displaying information on the selection of radio and wireless communication stations and sound volume, and its control switch <b>160</b>.

A gearshift REVERSE display lamp <b>111</b>, a NEUTRAL display lamp <b>112</b>, an oil indicator <b>114</b>, and a fuel injection (FI) warning light <b>115</b> are disposed in the speedometer <b>110</b>. A light sensor <b>113</b> for light control is installed between the NEUTRAL display lamp <b>112</b> and the oil indicator <b>114</b>. Between the fuel gauge <b>130</b> and the water temperature gauge <b>140</b> are installed vertically in one row an AUTO CRUISE indicating lamp <b>131</b>, an AUTO CRUISE SET indicating lamp <b>132</b>, a HIGH-BEAM indicating lamp <b>141</b>, a SIDE STAND UP warning light <b>142</b>, and an ABS (anti-lock brake system) warning light <b>143</b>.

A light on-off indicator <b>144</b> is mounted on the left side of the ABS warning light <b>143</b>, and a fuel empty indicator <b>145</b> is mounted on the right side of the ABS warning light <b>143</b>. A clock <b>121</b> is mounted below the tachometer <b>120</b>. Blinker indicators <b>170</b> and <b>171</b> are provided in the upper right and left of the speedometer <b>110</b>.

FIG. 2 is a sectional view showing the structure of the meter unit <b>10</b>. In the drawing, the case of the meter unit <b>10</b> includes a lower case <b>101</b>, an upper case <b>103</b>, a bottom plate <b>104</b>, and a lens <b>106</b>. On the lower case <b>101</b> is installed a bolt <b>102</b>, by which the meter unit <b>10</b> is secured to the front cowling <b>11</b>. The upper case <b>103</b> is mounted at the front of the lower case <b>101</b>, and the lower case <b>101</b> is fitted with the case bottom plate <b>104</b>.

A translucent dial <b>117</b> is installed between the case bottom plate <b>104</b> and the upper case <b>103</b> which serves as the display surface of the instrument panel <b>100</b>. A liquid crystal panel <b>151</b> is located obliquely below the dial <b>117</b> as the body of the information display panel <b>150</b> which is supported by the stem <b>101</b><i>a </i>raised from the lower case <b>101</b>. As illustrated, between the dial <b>117</b> and the liquid crystal panel <b>151</b> there is a difference in level. The surface of the liquid crystal panel <b>151</b> is set in a position closer to the rider's eyes.

The shaft of the pointer <b>118</b> is installed through the dial <b>117</b>, and the light sensor <b>113</b> is installed with its forward end exposed on the dial <b>117</b>. Also installed are a driving unit <b>119</b> of the pointer <b>118</b>, a lead (leg portion <b>113</b><i>a </i>of the light sensor <b>113</b>), and a lamp <b>105</b> applying the light translucently from behind the dial <b>117</b> to illuminate characters or graphic symbols. Also provided are a lead <b>113</b><i>a, </i>and light shield identified as a plate <b>152</b> for surrounding and covering the lower part of the head of the light sensor <b>113</b> to thereby prevent the direct incidence of light from the lamp <b>105</b> to the light sensor <b>113</b>. Because of the use of this plate <b>152</b>, the sensor <b>113</b> can accurately adjust the external light without an influence of the light of the lamp <b>105</b>.

A photoelectric transducer element such as a phototransistor is used as the light sensor <b>113</b>, which outputs the luminance to the later-described light control device, that is, a signal corresponding to the light intensity over the dial <b>117</b>. The light control device functions to determine the luminance on the basis of the characteristic and output of the light sensor, then controlling the luminance of the lamp <b>105</b> to a predetermined value. An acrylic resin lens <b>106</b> is used at the front of the meter unit <b>10</b> to protect each component. The lens <b>106</b> is so formed as to cover both the instrument panel <b>100</b> and the information display panel all together. The use of this lens <b>106</b> can simplify the lens molding and assembling processes more efficiently than separate lenses covering the instrument panel <b>100</b> and the information display panel <b>150</b>.

A panel cover <b>122</b> is mounted at the front of the meter unit <b>10</b>. For the panel cover <b>122</b>, refer to the perspective view of FIG. <b>3</b>. The panel cover <b>122</b> is formed to cover both the meter unit <b>10</b> and the right and left speaker panels (not shown) as one body. Holes <b>120</b><i>a </i>and <b>110</b><i>a </i>formed in the panel cover <b>122</b> align with the display position of the tachometer <b>120</b> and the speedometer <b>110</b> respectively. The hole <b>130</b><i>a </i>is formed to correspond to the display position of the fuel gauge <b>130</b> and the water temperature gauge <b>140</b>. Furthermore, the hole <b>150</b><i>a </i>is so formed as to correspond to the display position of the information display panel <b>150</b>.

The upper overhang section <b>122</b><i>a </i>of the panel cover <b>122</b> forms a part of the visor <b>50</b> for the instrument panel <b>100</b>, while the lower overhang section <b>122</b><i>b </i>forms a visor for the information display panel <b>150</b>. The top end of the overhang section <b>122</b><i>a </i>is covered with the body <b>50</b><i>a </i>of the visor <b>50</b> extending upwardly toward the rider. The lower part of the visor body <b>50</b><i>a </i>is secured, together with the meter unit <b>10</b>, to a non-illustrated stay covered with the front cowling <b>11</b>.

FIG. 4 is a block diagram showing the structure of a major portion of the light adjusting device. In the drawing, the light sensor <b>113</b> produces a light current corresponding to the intensity of the incident light. The light current is converted into a digital signal by an A/D converter <b>51</b>. At the comparison section <b>52</b>, the digital signal is compared with the reference illumination value Lref. The comparison section <b>52</b> outputs, to the light control device <b>53</b>, an Up signal when the value of the digital signal thus compared is less than the reference illumination value Lref, and a Dn signal when the value of the digital signal is greater than the reference illumination value Lref. The reference illumination value Lref has a dead zone for stabilization of operation. The light control device <b>53</b> responds to a signal outputted from the comparison section <b>52</b>. In the case of the Up signal, the current to be supplied from the power source <b>54</b> to the lamp <b>105</b> is increased. Conversely, in the case of the Dn signal, the current to be supplied from the power source <b>54</b> to the lamp <b>105</b> is decreased.

In the present embodiment, the illumination on the display surface of the instrument panel <b>100</b> where information are practically displayed is detected, to thereby enable controlling the luminance of the light source to a reference value.

According to the present invention, results of measurements of vehicle speed, engine speed, etc. are displayed, and at this time, the illumination on the surface of the instrument panel is measured to thereby provide the proper illumination for the driver's direct view to the display. Furthermore, since the light sensor is housed inside of the case, it is possible to protect the characteristics of the light sensor from deterioration likely to be caused by infrared and ultraviolet rays included in the external light.

Furthermore, it is possible to accurately detect and control the illumination in relation to a change in the external light without a direct influence of the light of the lighting means which illuminates the instrument panel.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.